Mitogenic response of near-diploid mouse cell line m5S/1M induced by epidermal growth factor.
A nonmalignant near-diploid cell line m5s/1M, established by Sasaki and Kodama (J. Cell. Res., 131:114-122, 1987), was shown to respond to the epidermal growth factor (EGF). The m5s/1M cells showed high sensitivity to post-confluence inhibition of cell division and formed a uniform monolayer after the cells had become confluent. The addition of EGF resulted in loss of contact-dependent inhibition of growth and caused a massive piling up of a multilayered array of cells after they had become confluent. When EGF was removed from the medium, the cell number decreased rapidly, and the cells formed a uniform monolayer at the density observed in the absence of EGF. m5S/1M cells have high- and low-affinity receptors for EGF (approximately 40,000 receptors per cell), and the apparent dissociation constants of the EGF-binding reactions were 3.3 nM and 0.15 nM, respectively. The effect of EGF on the intracellular mobilization of Ca2+ and the formation of inositol phosphates was studied by using the calcium-sensitive fluorescent indicator fura 2 and [3H]inositol. EGF had no effect either on the mobilization of cytosolic free calcium [( Ca2+]i) or on the formation of inositol phosphates in m5s/1M cells, whereas bradykinin induced a rapid increase in both [Ca2+]i and inositol phosphates. Analysis of the glycosphingolipid (GSL) composition of m5S/1M cells showed that globotriaosylceramide (Gb3Cer), which is known to be a Burkitt lymphoma-associated antigen, is specifically expressed in the EGF-treated cells. The expression of Gb3Cer is dependent on the presence of EGF, with a reversible shift in GSL composition being observed in the presence or absence of EGF.
Watanabe
S
S
Shionogi Research Laboratories, Shionogi & Co., Ltd., Osaka, Japan.
Umeda
M
M
Nomura
T
T
Kobayashi
T
T
Nakano
T
T
Arita
H
H
Utsumi
H
H
Sasaki
M S
MS
Inoue
K
K
D000818:Animals; D002118:Calcium / Q000378:metabolism; D002250:Carbon Radioisotopes / Q000378:metabolism; D002455:Cell Division / Q000187:drug effects; D002460:Cell Line; D004171:Diploidy; D004815:Epidermal Growth Factor / Q000378:metabolism / Q000494:pharmacology*; D005347:Fibroblasts / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D005915:Globosides / Q000378:metabolism; D006028:Glycosphingolipids / Q000378:metabolism; D007295:Inositol Phosphates / Q000378:metabolism; D051379:Mice; D008938:Mitosis / Q000187:drug effects*; D010169:Palmitic Acids / Q000378:metabolism; D014281:Trihexosylceramides
D002250:Carbon Radioisotopes; D005915:Globosides; D006028:Glycosphingolipids; D007295:Inositol Phosphates; D010169:Palmitic Acids; D014281:Trihexosylceramides; D004815:Epidermal Growth Factor; C018549:globotriaosylceramide; D002118:Calcium